Animal remedies for sheep, cattle and other livestock/production animals are applied by a number of methods including topical or “pour-on” application, oral “drench” application, injection and nasal infusion. Each of these administration routes is typically dispensed from a “pistol grip” style dispensing means. Such an applicator is described in the applicant's New Zealand patent No. 521084, the contents of which are herein incorporated by reference.
Conventional fluid applicators have incorporated two, one-way valves (inlet and outlet). Such valves are typically biased with springs, so that they open only when there is a predefined difference in the fluid pressure between the upstream side of the valve and the downstream side. Fluid cannot flow backwards through either valve, as flow in this direction will tend to push the valves more tightly closed. When the applicator is at rest, both valves are closed. When the applicator is in use, it is intended that only one valve opens at a time. During the discharge stroke, the outlet valve is pushed open by the raised fluid pressure within the barrel. During the refill stroke, the inlet valve is pushed open by fluid entering the barrel (where there is now a partial vacuum).
A problem with conventional applicators is that they require a relatively large force to squeeze the handles together during the application stroke of the piston. This may be fatiguing for the operator, particularly when the applicator is used to treat a large group of animals. In response to this problem, Applicants developed the BREAZE™ Technology, which is fully disclosed in patent AU 2013100370, the contents of which are herein incorporated by reference it their entirety. FIGS. 1-2 depict some of the key features of the BREAZE™ applicator, which requires a significantly smaller amount of force to squeeze as compared to predecessor dosing gun devices.
Although the BREAZE™ technology significantly improved upon “harder to squeeze” prior art devices, it would be useful to build on this technology to develop an applicator which allows for the delivery of two or more fluids. Such a device would allow for more efficient delivery of fluids that must be stored separately (e.g. active ingredient substances which are not readily co-formulated). Moreover, it would be desirable to develop devices capable of delivering even larger volumes of fluid, while maintaining the low squeeze strength requirement of the original, single chamber, single formulations BREAZE™ applicators. Finally, to produce acceptable ergonomics for such a device, it would be highly desirable to reverse the applicator's configuration, such that the dosing chambers/barrels are situated above the users wrist instead of in front of the applicator.